Process for preventing preignition in internal combustion engines



Patented July 19, 1932 UNITED STATES PATENT OFFICE ALBERT JEAN DUCAMP, OF VERSAILLES, FRANCE rnocnss r03. rBEvENTiNe rnEiGNrrIoN IN INTERNAL COMBUSTION ENGINES No Drawing. Original application filed March 9, 1929, Serial No. 345,878, and in France Mareh24, 1928. Divided and this application filed January 23, 1931. Serial No. 510,851.

The present a plication is a division from my application erial No. 345,87 8 filed March 9th 1929. 1

The present invention has reference to i processes and composition for preventing I pro-ignition in internal combustion engines.

One object of the invention is to use the lubricating oil of the engine as a carrier for introducing an anti-knock composition into the cylinders of the engine, it being understood that by an anti-knock composition is meant a composition calculated to prevent the occurence of pre-ignition.

I Another object of the invention is to use mercury cyanide toform ananti-knock composition. I

As is well known, during the suction stroke of a four-stroke engine for example, the piston moves down. and the walls of the cylin- 90 der, covered by a film of lubricating oil, are

in contact with the in-drawn gases which are in a state of turbulence. Such contact lasts through the second or compressionstroke and it is known that a certain proportion of the .15 lubricating oil in question mixes with the fuel and burns during combustion. For example, ly designed explosion engine will have an oil consumption, due to combustion, equal to at least one per cent by weight of its fuel consumption., knock material be introduced into the lubricating oil, the fuel will burn in the presence of one ten thousandth part of anti-knock substance.

One way of carrying out the process consists in dissolving the anti-knock substance in a combustible or non-combustible solvent, for example in glycerine to which phenol may or r 40 may not be added and in suspending the glycerine or other solvent containing the antiknock substance in a the lubricating oil. When the lubricatin oil is a mineral .oil formed of hydrocar ons, free, fatty and it is generally assumed that a proper-' 1 Hence, if one per cent of anti-- Naturally, if the lubricating oil be a fatty oil, the glycerine with its anti-knock content is suspended in the same manner which consists in considerably lowering, by means of an emulsion producing agent the inter-surface tension between the liquid containing the anti-knock substance and the lubricating oil.

For example, glycerine containing 20% by weight of mercury cyanide may be utilized and 10% by weight of said glycerine may be suspended in the lubricating oil. There will be finally 2% of anti-knock compound in 'the lubricating oil and if the oil burned by the engine is 2% by weight of the fuel, the percentage of mercury cyanide in terms of fuel will be 2%of 2%, i.'e. 04%.

The process is particularly applicable to lubricating oils which have the property of burning at comparatively low temperatures. Such lubricating oils burn very readily during the combustion of thefuel and constitute a particularly appropriate carrier for the anti-knock compound;

I claim 1.;An anti-knock composition for use in internal combustion engines, consisting of a mercury cyanide dissolved in glycerine and suspended in the lubricating oil of the engine cylinders. 2.. An anti-knock composition for use in internal combustion engines, consistingof a mercury, cyanide dissolved in glycerme mixed with a fatty acid and suspended in the lubricating oil of the engine cylinders.

3. An anti-knock composition for use in internal combustion engines, consisting of a mercury cyanide dissolved in glycerine mixed with a fatty substance containing an alkali and suspended in the lubricating oil of the engine cylinders.

ALBERT JEAN DUCANUP.

.3 preferably oxidized acids or alkaline or preferably alkaline-earth soaps, magnesium or calcium oleate for example, may be used as agents for suspending the glycerine in the hydrocarbons. Other suspending I agents 50 may likewise be used. 

